Author
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Johnson, Wiley - Carroll |
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MULLINIX JR, B - UNIVERSITY OF GEORGIA |
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Submitted to: Weed Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/5/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Yellow nutsedge is a perennial weed common in the southeastern coastal plain. Losses from yellow nutsedge include yield reduction from competition, allelopathy, tuber contamination in the harvested commodity, and cost of control. Chemical control measures are expensive and perform erratically. In order to more effectively manage yellow nutsedge, cultural weed control practices, such as crop rotations, were studied from 1990 through 1994 near Tifton, GA on the population dynamics of yellow nutsedge in peanut-corn and peanut-cotton rotations. Continuous fallow plots were included for comparison. Within each crop were three levels of weed management; low, moderate, and intensive. Yellow nutsedge density and numbers of tubers were not affected by crop rotations, but were affected by ycrops in the rotation sequence and weed management systems. Fallow plots consistently had more yellow nutsedge plants and tubers than other plots. Moderate and intensive weed control systems in peanut and cotton reduced yellow nutsedge densities and tubers. Weed management systems did not affect yellow nutsedge densities in corn, although yields were increased by moderate and intensive systems due to improved control of other weeds. These results incidated that over a 5 year period yellow nutsedge densities were not affected by crop rotations, but were affected by crops and levels of weed management. Uninterrupted plantings of peanut, corn, or cotton with moderate levels of weed management are generally sufficient to suppress yellow nutsedge and allow for optimum crop yield. If fields are periodically fallowed, yellow nutsedge will increase exponentially. Technical Abstract: Studies were conducted from 1990 through 1994 near Tifton, GA on the population dynamics of yellow nutsedge and certain annual weeds in peanut- corn and peanut-cotton rotations. Mirror images of the crop rotations were included to eliminate year effects. Continuous fallow plots (non-crop) were included for comparison. Within each crop, including fallow, were three levels of weed management; low, moderate, and intensive. Weed densities and numbers of yellow nutsedge tubers were not affected by crop rotations, but were affected by crops in the rotation sequence and weed management systems in each crop. Fallow plots, including those with intensive fallow weed management using tillage and nonselective herbicides, consistently contained more yellow nutsedge plants and tubers than other plots. Moderate and intensive weed control systems in peanut and cotton reduced yellow nutsedge densities and tubers, but only peanut yields were increased by intensive weed management. Weed management systems did not affect yellow nutsedge densities in corn, although yields were increased by moderate and intensive systems due to improved control of other weeds. These results indicated that over a 5 year period yellow nutsedge densities were not affected by crop rotations, but were affected by crops and levels of weed management. Uninterrupted plantings of peanut, corn, or cotton with moderate levels of weed management are generally sufficient to suppress yellow nutsedge and allow for optimum crop yield. If fields are fallow, yellow nutsedge population densities and tubers will increase exponentially, even with intensive fallow weed management. |
